TCP SYN (JA4T)

65535_2-4-8-1-3_1360_13

first seen 2026-06-30 18:02 · last seen 2026-09-16 02:16 · JSON

Last 7 days (8 observations)

Distinct clients per day (last 30 days, peak 1/day)

Distinct clients are counted by IP-hash per complete UTC day — unlike observation counts this is insensitive to one chatty client, but NAT merges clients and address rotation splits them.

Decomposed attributes

TCP window65535
Option kinds2-4-8-1-3
MSS1360
Window scale13

Co-observed signals

Signals from other families seen in the same observation. A fingerprint spread thinly across many lower-layer signatures is a classic inconsistency signal.

TLS ClientHello (JA4)

fingerprintco-occurrences
t13d2013h2_a09f3c656075_7f0f34a4126d Match?Exact match in Thumbprint's published controlled catalog captures: safari 26.5.2, safari 26.4, safari 26.6.2, +2 more.The fingerprint page shows the full measured match list. More on the catalog.16
t13d1511h2_8daaf6152771_78e6aca7449b8
t13d1516h2_8daaf6152771_806a8c22fdea Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chrome 151.0.7922.137, chromium 151.0.7922.34, +24 more.The fingerprint page shows the full measured match list. More on the catalog.7
t13d1518h2_8daaf6152771_4980c97edce07
t13d131100_f57a46bbacb6_ab7e3b40a677 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.5, go-net/http 1.26.4.The fingerprint page shows the full measured match list. More on the catalog.5
t13d0911h2_e58ff226e52e_78e6aca7449b3
t12d210700_76e208dd3e22_2dae41c691ec2
t13d4907h2_0d8feac7bc37_7395dae3b2f3 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1.The fingerprint page shows the full measured match list. More on the catalog.2
t13d1516h2_8daaf6152771_d8a2da3f94cd Match?Exact match in Thumbprint's published controlled catalog captures: chromium 149.0.7827.102, chrome 149.0.7827.102, chrome 149.0.7827.156, +25 more.The fingerprint page shows the full measured match list. More on the catalog.1
t13d1812h1_5d04281c6031_ef7df7f74e481

HTTP request (JA4H)

fingerprintco-occurrences
ge20nr09engb_538441e4e116_000000000000_0000000000006
ge20nr12engb_54b4638ab28b_000000000000_0000000000004
ge20nr12enus_f8a3a1e39dc3_000000000000_0000000000004
ge20nr12idid_54b4638ab28b_000000000000_0000000000003
he11nr030000_69803879d94f_000000000000_0000000000003
ge11nn050000_2469c960a647_000000000000_0000000000002
ge20nr09engb_d05bf764aa1e_000000000000_0000000000002
ge20nr09enus_538441e4e116_000000000000_0000000000002
ge20nn10engb_f7ad313dcc59_000000000000_0000000000002
ge20nr08engb_1945e0741196_000000000000_0000000000002

HTTP/2 frames (Akamai)

fingerprintco-occurrences
2:0;3:100;4:2097152;9:1|10420225|0|m,s,a,p Match?Exact match in Thumbprint's published controlled catalog captures: safari 26.5.2, safari 26.5, safari 26.4, +2 more.The fingerprint page shows the full measured match list. More on the catalog.16
2:0;4:2097152;5:16384;6:16777216|5177345|0|m,s,a,p11
1:65536;2:0;4:6291456;6:262144|15663105|1:1:0:220|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chromium 149.0.7827.102, chrome 149.0.7827.102, +59 more.The fingerprint page shows the full measured match list. More on the catalog.7
1:65536;2:0;4:6291456;6:262144|15663105|1:1:0:256|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chromium 131.0.6778.33, chromium 151.0.7922.34, chrome 151.0.7922.137, +43 more.The fingerprint page shows the full measured match list. More on the catalog.4
3:100;4:10485760;2:0|1048510465|0|m,s,a,p Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1, curl 8.5.0.The fingerprint page shows the full measured match list. More on the catalog.2
1:65536;2:0;4:6291456;6:262144|15663105|3:1:0:220|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chromium 151.0.7922.34, chromium 147.0.7727.15, chromium 145.0.7632.6, +21 more.The fingerprint page shows the full measured match list. More on the catalog.2
1:65536;2:0;4:6291456;6:262144|15663105|7:1:0:256|m,a,s,p1
1:65536;2:0;4:6291456;6:262144|15663105|5:1:0:220|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chromium 133.0.6943.16, chrome 150.0.7871.128, chromium 148.0.7778.96, +2 more.The fingerprint page shows the full measured match list. More on the catalog.1
1:65536;2:0;4:6291456;6:262144|15663105|3:1:0:256|m,a,s,p1

TCP SYN (p0f)

fingerprintco-occurrences
6:57+7:0:1360:65535,13:mss,sok,ts,nop,ws:flow:013
6:49+15:0:1360:65535,13:mss,sok,ts,nop,ws:flow:011
6:58+6:0:1360:65535,13:mss,sok,ts,nop,ws:flow:07
6:53+11:0:1360:65535,13:mss,sok,ts,nop,ws:flow:05
6:54+10:0:1360:65535,13:mss,sok,ts,nop,ws:flow:05
6:51+13:0:1360:65535,13:mss,sok,ts,nop,ws:flow:03
6:47+17:0:1360:65535,13:mss,sok,ts,nop,ws:flow:03
6:50+14:0:1360:65535,13:mss,sok,ts,nop,ws:flow:03
6:48+16:0:1360:65535,13:mss,sok,ts,nop,ws:flow:03
6:46+18:0:1360:65535,13:mss,sok,ts,nop,ws:flow:01

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/150.0.0.0 Safari/537.369
Mozilla/5.0 (iPhone; CPU iPhone OS 18_7 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.4 Mobile/15E148 Safari/604.18
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/153.0.0.0 Safari/537.367
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.107 Safari/537.36 (compatible; +https://developers.cloudflare.com/security-center/)5
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/150.0.0.0 Safari/537.364
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.5.2 Safari/605.1.154
Mozilla/5.0 (iPhone; CPU iPhone OS 18_7 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.6 Mobile/15E148 Safari/604.13
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/151.0.0.0 Safari/537.36 Edg/151.0.0.03
curl/8.7.12
Mozilla/5.0 (iPhone; CPU iPhone OS 18_7 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.5 Mobile/15E148 Safari/604.11

Country

fingerprintco-occurrences
US · United States21
IT · Italy8
NL · Netherlands7
AU · Australia5
ID · Indonesia4
NZ · New Zealand3
SG · Singapore2
FR · France2
UA · Ukraine1
FI · Finland1

Network (ASN)

fingerprintco-occurrences
AS13335 · Cloudflare, Inc.56

Cross-transport links

TLS ClientHello fingerprints observed from the same client via the beacon's correlation id on the other transport (e.g. this stack over TCP ↔ that stack over QUIC).

fingerprintlinked observations
q13d0311h3_55b375c5d22e_653d80c3fe9d5
q13d0311h3_55b375c5d22e_f2a83c8e78ae4
q13d0312h3_55b375c5d22e_178839b6cec11